Ask around in your area if there is someone that has the technical ability to electrically reverse the servo inside it's case.

It's a relatively simple matter of reversing the wires on the motor and the ones on the outer edge of the pot, but it can be done.

Even the new ones with the motor soldered directly to the PC board can be reversed.

I do it all the time.

Just make sure you mark the case with a big "R"...